Injector nozzle



PatentedAug. 8; 1939 UNITED STAT-ss PATENT OFFICE;

2 Claims.

'I'his invention relates to fuel injectors for internal combustion engines and has particular reference to an improved unitary injector and nozzle for use with Diesel engines.

A n object of the invention is the provisionv of a fuel injector for use with a Diesel engine which is so constructedas to utilize the high pressure developed within the combustion chamber of the engine as assistance to forcethe fuel from the injector into the engine.

Another object of the invention is the provision of a fuel injector andnozzle in which the' working stresses are materially reduced.

VAnother object of the invention is the provision of a device of the character referred to which is simple in construction', economical to manufacture and easy to install.

nozzles as now usedvin connection with Diesel engines. K

Another object of the invention is the provision of a device for the injection of fuel into aninternal combustion engine which has a quick and positive shut-oit action thereby eliminating an'y possibility o f the dribbling of fuel.

Further objects and advantages of the invention will appear as the description proceeds, reference being made from time to time to the ac.

companying drawings constituting part of the` disclosure, in which drawings:

a. device embodying the invention (line I 'I .of Fig. L and illustrates the manner in which it may be secured to the block of a Diesel engine. Fig. '2 is van end view of the device illustrated in Fig. 1. Fig. 3 is a vertical section taken on the 'line `3-3 of Fig. 1.

Fig'. 41s a vertical section taken on the line 4-4 of Fig. 2. Fig. 5 is a section taken Fig. 6 is an enlarged detail of the fuel by-pass gate.

Fig. '7 is an endV view of the delivery valve. 8 is aside view of the delivery valve. Fig. 9 is an enlargeddetail'of the plunger bar- .reL

Referring now more particularly to the drawonV the line 5-5 of (ci. 29e-107,2)

ings', it will be seen that the device embodying my' Ainvention consists Aof a cylindrical body member I2 which may be made of gray iron machined to tightly fit into a recess I3 bored in a boss I4 formed on the side of the cylinder block of a 5v I Diesel engine, a fragmentary portion of-Which is indicated by the reference-character' I5. The body I2 is preferably secured in position by means Y oi bolts I6, which extend through the end plate I1 into`internally threaded recesses I8 `formed in l0 the boss I4. The end plate I1 is arranged to serve as a closure element-for one end of the body I2 and is adapted to support the end cover I9, which is preferably made of' pressed metal formed with re-enforcing elements 20, and sel5` cured to the end plate I1 by means of llister head screws 2I. 'v

Press-tted into the i'nternal bore of the body member I2 is a sleeve 22, which isformed with a collar 23 at one end, adapted to engage a shoul- 20 der 24 formed in the body I2. The collar 23 serves to prevent displacement ofthe sleeve 22 in one direction,`and the end plate II prevents the sleeve'from being displaced in the opposite direction. A plunger 25 is.mounted for reciprocation 25 in the sleeve 22. This .plunger (Fig. 9) is provided With an internal bore 26, in which is mounted the working parts hereinafter described. As illustrated in Fig. 9, the plunger is slotted as at 25a.v` so that it may vbe extended through suitable 30 openings 25h (Fig. 2) formed in the end plate I1. The internalbore 26 is threaded as at 21 andis arranged to receive a threaded plug 28; which in turn' is provided with an internal passageway 29. Between the plug 28 and the end of the bore -35 2l'is a.. restricted area 30 in"which is slid'ably mounted a delivery valve 3I, which 'is provided with angularly positioned passageways 33, which are arranged to communicate with the passageway 29 in the plug 28. A compression spring 34 40l is arranged to normally maintain the valve- 3| in the closed position shown in Fig. 1. 'Ihe compression Vof this spring must be suicient to allow apredetermined pressure to be builtup in chamber 3|! The greater the pressure in chamber 45 38, better the fuel will be atomized during delivery. A burner plate 35 is threaded mounted in. an internally threaded recess formed in the end -of the plunger 25 andhas a small axial passageway 36 arranged to communicate with a 50 similar but larger in diameter axial passageway formed' in the plunger 25. rIrhe plunger 25 is provided with. compression rings 31 which are arranged to seal Icompression and stop compression loss from the combustion .chamber of the' 55 engine. A compression'chamber 38 is formed in the plunger 25 and in aportion of the body I2, and communicates` at one end with a passageway 39 whichextends through the plunger 25, the

sleeve 22 and the body |2, and which in'turn is connected toa fuel transfer pump (not shown) which moves the fuel from the main fuel tank. -The other end of the compression chamber 38 'communicates with the passageway 40, which'4 also passes through the body I2 of the injector,l and in turn is connected to the fueltank or fuel line below the transfer pump and adapted to permit the return of by-passed fuel to the main tank orreservoir as hereinafter described.

In order to control the amount of fuel to be yby-passed from the compression chamber 38, I provide a by-pass gate 4| which is arranged to reciprocate in a slot 42 formed in one side of the sleeve 22. on its under side with a rack 43 adapted to engage a pinion 44 mounted on a shaft 45, the latter being preferably connected to manually operable means for rotating the same in order that the by-pass gate 4| may be moved forward or backward. The by-pass gate 4| (Fig. 6 is provided -on either side with a tongue arranged to slidably engage the corresponding grooves formed in the side walls of the slot 42. A core 46 is mounted in the internal bore 25 of the plunger- 25 and is secured against displacement by means of the machine screw 41, which extends through an aperture in theend plate l1, and engages an internally threaded bore formed in the end of the core. A fiber washer 46a is'positioned between the end of the core 45 and the end plate l1. The core 46 is provided with oil grooves 48 which are adapted to trap any fuel oil that may escape fronl the compression cham-l ber 38. The oil'thus trapped in the grooves 48 serves to lubricate thebearing surfaces between the plunger 25 and the core 46. A compression V spiing49 is mounted in a counterbore 50 formed in the end of the plunger 25, and is adjustable by means ofthe adjusting screw 5|,which threadedly engages an opening in the end of the end cover I9. A'roller 52 is mounted for rotation on an axle supported at either end in a roller holder 53, which is secured by. bolts 53a to the end plate |1. A second roller 54 is mounted for rotation' on a suitable axis 55, secured by bolts 58 to the opposite sides of the plunger 25. Interposed between the rollers 52 and 54 (Fig. 4) is a l wedge-shaped member 51 which is mounted at the end o f a push rod 58 at the opposite end of which is mounted a roller 5.3- adapted to be actuated by a suitably timed cam 80, the latter being 1 48. It will be understood lthat the cam actuated wedge is timed to operate and cause the plunger to start to move away from the combustion chamber of theengine as the compression reaches its maximum in the cylinder of the engine. with this arrangement the movement of the plunger is then assisted by the compression of the motor itself. This is an advantageous feature of my invention and enablesthis'device to be operated with much less stress and strain than encountered in devices. ofl this kind. heretofore known. It-

will be understood that the compression ofthespring 48 `will be adjusted by means of the screw i The by-pass gate 4| is provided' 5i so that its compression will just overcome the maximum pressure in the cylinder so as to hold the plunger in closed position.

ary core 46 and the plug 28 which is mounted in j the reciprocable 4plunger 25.4 As the plunger 25 is moved to the left under the inuence of the property timed cam operated wedge 51 and the increasedcompression in the cylinder of the engine, the fuel in the compression chamber 38 I 'can only escape in two directions, either around the by-pass gate 4| into the passageway 44 and hence return to the fuel tank or supply line, or

through the axial passageway 29 formed in the plug 28 and through the angular passageways I 33 formed in the valve 3| and into the space between the valve 3| and the plunger 25 and hence through the axial passageway in the plunger 25 and the burner plate 35 and into the combustion chamber of the engine. By moving the by-pass gate forward and backward the by-pass clearance in the chamber 38 is either increased or diminished. As the by-pass clearance is decreased in the chamber 38, there is an increased amount of fuel injected through the valve 3| into the engine and as the by-pass clearance is increased there is a decreased amount of fuel forced through the valve 3| into the engine.

As the plunger is movedto the left (Fig. 1) the first part of the stroke is ineffective to discharge oil past the valve 3l for in this position the by-pass gate 4| isV open and the fuel will be by-passed through the passageway 40. As the plunger continuesto move to the left, the bypass clearance will be reduced and finally closed l thereby building up pressure in the chamber 38. While the by-pass 4| is. open, the outlet ports 33a of the angular passageways 33 in the valve 3| are still covered by the walls of the restrictedarea 30. As the plunger 25 continues to move i to the left, closing the by-pass 4|, the unrestricted area of the internal bore of the plunger 25 communicates with the outlet ports 33a of the valve 3| thus permitting the fuel to pass around the end of the valvev 3| and hence into the axial passageway formed through the plunger 25. When the plunger has reached the limit of its travel to the left, it will be returned to the posi- 4tion shown in Fig. 1 by means of the spring 48.

As the. plunger returns to the position shown in Fig. 1, it is evident that the valve stops delivering fuel before the valve is fully seated because the outlet ports V33a will be covered before the valv 3| is seated.

Although I have herein disclosed the preferred embodiment of my invention, it .will be understood' that certain modifications may be made all of which are intended to bev within the scope of the appendedclaims.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a device of the character described, the

combination of a body member adapted to be I secured toan internal combustion engine and Ihaving a `bore adaptedto communicate with the combustion chamber of said engine, a sleeve in said borea plunger mounted f or reciprocation in said sleeve, spring means arranged to move said plunger towards said engine, means timed with said engine to move said plunger away from said engine, a'longitudinal bore in said plunger, va stationary core in said last-namedbore, there being a compression chamber between 'one end of 'said last named bore and said core, a fuel inlet communicating with said compression chamber, outlets communicating with said chamber, one of said outlets comprisingl a by-pass controlled by a gate slidable in Aa recess Aformed .y in said sleeve, saidother outlets being arranged ber into said combustion chamber upon themnve to discharge fuelfrom said compression chamment of the plunger in the direction away `from said combustion chamber.

' 2. 'An injector nozzle comprising tion of a body member having a plunger recip- "rocable therein, an axial bore in said plunger. a

restricted area in said bore, astationary core in said boref uel intake and fuel exhaust ports the combina? ,3 communicating lwith said bore, a valve 'siidabiy mounted in said restricted area invsaicl bore,- a

fbe unseated, by fuel pressure -built up in said bore, lupon movement of the'v plunger carrying said valve-seat member towards said stationary core, an end plate for said body member, an end f cover member supported by said end plate, ad-

instable spring means carried by' said end cover member for moving said plunger away from said end cover member and.- timed means for movingI said plunger toward said end cover member. t

- ANDREW J. DAVIDSON, Jn'. 

